VBA: Option Explicit

[AD_Taylor]

I know that if you add Option Explicit to the top of a code module, you have to explicitly declare all variables used (which really helps me as I misspell variables a lot)

However if I do misspell one further on down, what happens?
Assuming I have 'On Error Resume Next' activated I won't see the error, so I'll just get very strange results from running the code?

Is there a check I can do, to make sure that all variable definitions are declared?

I.e. Check through a code module and if for example:

undeclaredVar = Cells(1, 1).Value

an undeclared variable is found it would highlight it?

 

[VoG]

In the VBE, Debug > Compile VBA Project.

 

[AD_Taylor]

Thanks Peter

Shows how much I still have to learn about the VBE Editor! I might know the code but I still don't use the menu items as well as I could.

 

[Ruddles]

Option Explicit is a compiler directive - it is interpreted at compile time before the program even starts running. If your program includes a variable which isn't declared - perhaps you misspelled it - then VBA will report this at compile time and your program won't even start executing.

On Error commands are interpreted at run-time - they can only trap error which occur during program execution. If you had an undeclared variable and Option Explicit, your program would never have got as far as the On Error command.